Urdnan, Dromoka Warrior (Anime) (34) [Foundations Jumpstart]

When Urdnan enters, put a +1/+1 counter on target creature. Whenever you attack, target attacking creature with a +1/+1 counter on it gains first strike until end of turn. If that creature has two or more +1/+1 counters on it, it gains double strike until end of turn instead.